1. Field of the Invention
The present invention relates to medical instruments and, more particularly, to an endoscope.
2. Prior Art
U.S. Pat. No. 5,807,240 discloses a continuous flow resectoscope with a sheath assembly having two tubes; an inner tube and an outer tube. U.S. Pat. No. 5,486,155 discloses a rotatable endoscope sheath. U.S. Pat. No. 5,857,962 discloses a resectoscope with a movable actuator assembly. A problem with prior art continuous flow endoscopes is that smaller diameter shafts are desirable, but reducing the diameter of a shaft causes problems regarding sufficient flow of fluid into and out of the patient through the shaft. Another problem is that it is desirable to use existing telescopes, thus, making a reduction in shaft diameter cause fluid flow problems.
In accordance with one embodiment of the present invention, a continuous flow endoscope is provided comprising a working element and an outer sheath assembly. The working element comprises a frame including a telescope guide tube and a fluid passage through the frame and into the telescope guide tube. The outer sheath assembly is connected to the frame. The outer sheath assembly comprises an outer tube located around a portion of the telescope guide tube. The outer tube and the telescope guide tube form a fluid outflow conduit therebetween along a majority of the length of the outer tube.
In accordance with another embodiment of the present invention, an endoscope working element is provided comprising a frame and a movable portion. The frame includes a telescope guide tube. The movable portion is movably mounted to the frame. The telescope guide tube has a first cross-sectional shape along a majority of a length of the guide tube and a second different cross-sectional shape along a front end section of the guide tube.
In accordance with another embodiment of the present invention, a continuous flow or non-continuous flow endoscope outer sheath assembly is provided comprising a tube, a connector and an insulating tip. The connector is located at a rear end of the tube. The connector comprises a first mount for attaching a first fluid conduit to the connector. The insulating tip is directly connected to the front end of the tube.
In accordance with another embodiment of the present invention, a continuous flow endoscope is provided comprising a working element and a sheath assembly. The working element comprises a frame and a rotatable sheath connector connected directly to the frame. The sheath assembly is connected to the working element. The sheath assembly comprises a rear end connector directly connected to the rotatable sheath connector. The rear end connector comprises two fluid conduit mounts for attaching two fluid conduits to the outer sheath assembly. The working element and the sheath assembly are directly rotatably connected to each other by the rotatable sheath connector.
In accordance with another embodiment of the present invention, a non-continuous flow endoscope is provided comprising a working element comprising a frame and a rotatable sheath connector connected directly to the frame, the frame comprising an inner tube; and a sheath assembly connected to the working element. The sheath assembly comprises an outer tube and a rear end connector directly connected to the rotatable sheath connector. The rear end connector comprises a fluid conduit mount for attaching a fluid conduit to the outer sheath assembly. The fluid conduit mount has a fluid flow passage which communicates with fluid flow passages along both the inner tube and the outer tube to a distal end of the endoscope. The working element and the sheath assembly are directly rotatably connected to each other by the rotatable sheath connector.